Project Summary

Evaluation of Splitting Saw Washing Procedures to Remove CNS Tissue

Principle Investigator(s):
M.B. Bowling, J.A. Scanga, K.E. Belk, K.L. Hossner, R.S. Yemm, J.N. Sofos, J.D. Tatum, and G.C. Smith
Colorado State University
Completion Date:
May 2006



In September of 2004, Helps et al. (2004) indicated that a common, commercial beef carcass splitting saw (Jarvis Buster VI, Middletown, CN) provides potential for cross-contamination of beef carcasses with potentially infectious nervous tissue. They determined that debris (central nervous tissue (CNS) tissue) remains inside saws despite attempts to sanitize them between splitting differing carcasses during operation. Consumption of CNS tissue infected with Bovine Spongiform Encephalopathy (BSE) has been linked with variant Creutzfeldt-Jakob Disease (vCJD) in humans (Williams, 1997). Additionally, the USDA Food Safety and Inspection Service (FSIS), in an Interim Final Rule issued January 12, 2004, designated tonsils and the small intestine from all cattle along with the spinal cord, brain, trigeminal ganglia, eyes, skull, and dorsal root ganglia of animals over 30 months of age as Specified Risk Materials (SRM) and prohibited them from entering the human food chain. Cross-contamination with CNS tissue via the splitting saw without further process interventions could result in a food safety threat. Immunochemical methods to detect presence of CNS tissue in or on meat products have been developed (Schmidt et al., 1999, 2001; Hossner et al., 2004). The favored method uses a fluorometric enzyme-linked immunosorbent assay (f-ELISA) for the detection of glial fibrillary acidic protein (GFAP). Glial fibrillary acidic protein is the major protein constituent of glial filaments in differentiated astrocytes which are mostly restricted to the CNS (Eng and Lee, 1995). Efficacy of the GFAP f-ELISA was examined for detection of CNS tissue in blood and muscle from beef cattle (Schmidt et al., 1999, 2001); the GFAP f-ELISA proved to be a simple, cost effective, safe and efficient method to detect minute quantities of CNS tissue in non-neural tissues of beef. 

The stated objectives for this work were: 

Using established saw washing standard operating procedures (SOP), in a controlled setting, identify two SOP’s to be subsequently evaluated on-line.

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